Introduction

In the last chapter, we covered a number of scenarios where you could securely publish servers on the internal network using server and Web publishing rules. In this chapter, we're going to focus on a single type of server: the mail server. In particular, we'll cover how to publish the IIS SMTP server and Microsoft Exchange 2000 Server. We won't discuss the specifics of publishing Exchange 5.5, but the general principles remain the same.

Mail services publishing is the most popular type of server publishing. Both small and large organizations prefer to have a higher level of control over their mail services than any other type of service. Why? Because most businesses are highly dependent on their mail services, they can little afford the foibles and inconsistent levels of service provided by third parties. If mail services go down, they might take the business with them!

The good news is that ISA Server makes publishing mail services very simple. If you have your own third-party SMTP/POP3 mail server, you can use the Microsoft IIS SMTP service for a mail relay, and you can even leverage the IIS SMTP service and the ISA Server Message Screener to protect your third-party SMTP/POP3 mail server from spam. If you run Windows 2003, you already have a POP3 server available to you. Just put an IIS SMTP service in front of your Windows 2003 SMTP/POP3 server and you'll be protected against attackers and spam.

Even more impressive than support for simple IIS SMTP...